Rafael Benitez has insisted that David Luiz only uses his elbow to protect himself, and said that his brilliant Brazilian was "miles better" than most Premier League players.

Luiz, who has been one of the best players in the country this season in both defence and midfield, was involved in another disagreement during Chelsea's 1-0 win at Manchester United on Sunday. Luiz appeared to put his arm across his compatriot Rafael, inducing a kick which saw the United right-back sent off.

Benitez said that while some players use their elbows aggressively, Luiz did so only for protection. "One thing is to protect the ball," Benitez said, "the other to hit someone with the elbow. He is trying to protect himself and the ball."

Sunday's spat was not the first such incident Luiz has been involved in this season. In last month's FA Cup semi-final he used an elbow on Manchester City striker Sergio Aguero, which led to the Argentinian's two-footed stamp. In an FA Cup game against Brentford, Luiz concussed Brentford's Jake Reeves with a reckless shoulder challenge.

Benitez admitted that at times Luiz's conduct was not perfect, adding: "It can be a negative, but he can improve it," the Chelsea manager said. "His game has a lot more positives than negatives. He is more mature and he will improve in his decisions around the game."

Benitez was keener to talk about Luiz's successes. "David Luiz is one of the best players in the Premier League, by miles," he said, "miles away from a lot of players and one of the best, without a doubt.

"The good thing about him is that he is really good now. He can do a lot of things, almost everything, really well, better than the majority of players. He is keen to learn. But he is still a young player and doing really well. He can become a lot better."

While Luiz's jovial style is not to everyone's taste – he was seen laughing after being kicked by Rafael on Sunday – Benitez said he was a fun but hard-working individual. "He's a person that likes to enjoy life and a very good professional, working very hard," Benitez said. "He likes to joke because he is a funny person but he can also be very serious, professional, and concentrate on his job.

"I don't see any problem with someone who has a good character but also a good mentality who wants to improve on the pitch."

Luiz has been one of the main successes of Benitez's tenure as Chelsea interim manager, which could end with a triumphant few weeks if his team beat Tottenham Hotspur at Stamford Bridge tomorrow night.

Victory would move Chelsea four points clear of Arsenal and six ahead of Spurs, giving them a huge chance of qualifying for the Champions League next season, with Aston Villa away and Everton at home their last two league fixtures.

Chelsea also have a Europa League final to play against Benfica in Amsterdam next week. There are signs of a softening of Chelsea fans' previously highly antagonistic views towards Benitez after recent successes.

"A lot of fans realise the job we're doing," Benitez said, before admitting he would be sad to leave Stamford Bridge. "When you are in a team and enjoying working with players and staff who are really good, and have a really good relationship with them, it's always a little bit sad when you have to go. But it's a part of our job now."

Chelsea's Belgian midfield star Eden Hazard should be fit for the game, having missed Sunday's victory at Old Trafford with a calf injury.

Chelsea report Benayoun abuse

Chelsea have alerted the Metropolitan Police over more anti-Semitic abuse of Yossi Benayoun, this time on Twitter, in the early hours of this morning. The incident comes just weeks after the Israeli midfielder said he had been the victim of anti-Semitic taunts from his own supporters when he came on as a substitute against Liverpool.

Chelsea will feature an enhanced anti-discrimination message in their programme before tonight's Spurs game.